The objectives of this study are: 1) to detemine the relationship between stress, mood, social support and coping and genital herpes simplex recurrence in a sample of patients with frequent outbreaks of the disease; and 2) to determine whether changes in natural killer (NK) cell activity and numbers of helper and suppressor T cells mediate the hypothesized relationship of psychosocial factors to recurrence. Eighty subjects with documented recurrent genital herpes will be assessed monthly for six months on the psychological measures (life stress, mood, social support and coping) and on health variables. Herpes recurrences will be verified by a physician. A subsample of 40 subjects will give blood samples monthly which will be assayed for percentage of helper and suppressor T-cells and for NK cell activity. Twenty control subjects who have never had genital herpes will monthly complete stress and mood questionnaires and provide blood samples which will be assayed on the same immunological parameters. Data analyses will examine which psychological factors result in an increased or decreased likelihood of herpes recurrences in the month follow-up period and whether these relationships are mediated by change in the numbers of helper and suppressor T cells or NK cell activity. The buffering effects of social support and coping will also be determined. This study uses recurrent genital herpes as a model to study the relationships among stress and emotional factors, immunological change and disease outcomes.